Premature infants face a host of unique issues due to their developmental immaturity. One of the most devastating is necrotizing enterocolitis (NEC), which yearly kills 12 babies per 100,000 live births in the US and frequently leaves survivors with severe feeding issues, liver failure, and neurodevelopmental disability. Understanding mechanisms of intestinal injury and repair in developing intestine is key to developing new prevention and therapeutic strategies for NEC. This proposal will investigate the mechanisms of gastrointestinal epithelial cell injury and repair during development by testing the hypothesis that the intestine of premature infants and newborn mice is more susceptible to TNF-induced injury because of an ontogenically normal decrease in expression and activation of EGFR. This hypothesis will be examined through the following specific Aims: 1) Define the effects of TNF on intestinal injury and apoptosis at different developmental stages. This will be accomplished using histopathologic injury scores of early intestinal damage as well as immunofluorescence and immunohistochemical assays for apoptosis;2) Determine the effects of TNF on EGFR inhibition in neonates compared to adults. We will study the effects of TNF on multiple EGFR phosphorylation sites and down-stream targets, and the role of EGFR internalization in TNF-stimulated EGFR inhibition.
This aim will utilize immunofluorescence and western blot analysis to study the down-stream targets of EGFR activation;and 3) Determine the role of EGFR activation in protecting against TNF induced injury using pharmacologic and genetic models of EGFR activation.
This aim will build on techniques developed in Aim 1 and 2 and apply them to mice with constitutively active EGFR, pharmacologically active EGFR, and deficiency of EGFR. Overall, these studies will reveal the roles of TNF and EGFR in intestinal injury processes in developing intestinal tissue, and will identify potential novel avenues of therapy and chemoprevention. In addition to the above studies, this proposal will greatly enhance career development through didactic training in cell biology, developmental biology, and statistics;by providing mentoring from a strong laboratory;and by utilizing the strong resources uniquely available at Vanderbilt to foster independent investigation in gastrointestinal disease.

Public Health Relevance

Necrotizing enterocolitis is a form of acute intestinal injury that is a leading cause of death and poor outcomes in premature infants. The studies in this proposal are intended to understand the mechanisms of injury and repair in the developing intestine of prematurely born infants, and the development of novel therapeutic approaches to prevent or ameliorate this devestating illness.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Clinical Investigator Award (CIA) (K08)
Project #
5K08DK083677-03
Application #
8089246
Study Section
Special Emphasis Panel (ZDK1-GRB-7 (J2))
Program Officer
Podskalny, Judith M,
Project Start
2009-07-01
Project End
2011-11-04
Budget Start
2011-07-01
Budget End
2011-11-04
Support Year
3
Fiscal Year
2011
Total Cost
$21,891
Indirect Cost
Name
Vanderbilt University Medical Center
Department
Pediatrics
Type
Schools of Medicine
DUNS #
004413456
City
Nashville
State
TN
Country
United States
Zip Code
37212
White, Jessica R; Gong, Huiyu; Pope, Brock et al. (2017) Paneth-cell-disruption-induced necrotizing enterocolitis in mice requires live bacteria and occurs independently of TLR4 signaling. Dis Model Mech 10:727-736
Fung, Camille M; White, Jessica R; Brown, Ashley S et al. (2016) Intrauterine Growth Restriction Alters Mouse Intestinal Architecture during Development. PLoS One 11:e0146542
White, Jessica R; Gong, Huiyu; Colaizy, Tarah T et al. (2016) Evaluation of hematologic variables in newborn C57/BL6 mice up to day 35. Vet Clin Pathol 45:87-95
Brown, Kathryn S; Gong, Huiyu; Frey, Mark R et al. (2014) Tumor necrosis factor induces developmental stage-dependent structural changes in the immature small intestine. Mediators Inflamm 2014:852378
McElroy, S J (2014) Unraveling the enigma that is neonatal necrotizing enterocolitis. J Perinatol 34:729-30
McElroy, Steven J; Castle, Shannon L; Bernard, Jessica K et al. (2014) The ErbB4 ligand neuregulin-4 protects against experimental necrotizing enterocolitis. Am J Pathol 184:2768-78
McElroy, Steven J; Underwood, Mark A; Sherman, Michael P (2013) Paneth cells and necrotizing enterocolitis: a novel hypothesis for disease pathogenesis. Neonatology 103:10-20
Gillam-Krakauer, M; Cochran, C M; Slaughter, J C et al. (2013) Correlation of abdominal rSO2 with superior mesenteric artery velocities in preterm infants. J Perinatol 33:609-12
Dubé, Philip E; Yan, Fang; Punit, Shivesh et al. (2012) Epidermal growth factor receptor inhibits colitis-associated cancer in mice. J Clin Invest 122:2780-92
McElroy, Steven J; Hobbs, Stuart; Kallen, Michael et al. (2012) Transactivation of EGFR by LPS induces COX-2 expression in enterocytes. PLoS One 7:e38373

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